package y23.Jun;
//判定一个数是否是素数
import java.util.Scanner;

public class Test1 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            int num = sc.nextInt();
            int count = 0;
            for(int i = 2;i <= num;i++){
                if(num % i == 0){
                    count++;
                }
            }
            if(count == 1){
                System.out.println(num);
            }else{
                System.out.println("不是素数");
            }
        }
    }
}
